The present invention relates to a flange fixture intended to hold a flange to a tube for welding the flange to said tube.
The object of the present invention is to obtain a flange fixture for eliminating assistance of further working power and thereby eliminating the human fault factor, as well as obtaining a simple and rational handling of the fixation of flanges to a tube, independent of any presence of bends on the intended tube or not.
At the welding of flanges onto tubes two men are used today, whereby one holds a flange by means of a gripping tool or by hand to the tube, whereupon the welder applies a number of point welds for fixation of the flange to the tube, whereupon a complete welding takes place along the whole abutment surface. Hereby the problem is to hold the flange in a correct position visavi the tube, on one hand what regards the distance, as distance of one to some millimeters is wanted in connection with the welding, on the other hand what regards the position of pre bored holes of the flange visavi the rotation and future connection of the tube to another flange. Hereby an intended rotation of two tubes in relation to each other be achieved as otherwise a complete mounting of a tube construction can become completely wrong. Further, the joint of the flange perpendicular to the longitudinal axis of the tube difficult to obtain in particular if the tube has not been cut perpendicular to said longitudinal axis, as the eye willingly follows a given line.
Hitherto, there has been no simple and rational construction to solve this problem, a construction which in a simple way can be handled at the individual place of work.
It has now surprisingly been shown possible to be able to solve this problem in a simple and rational way by means of the present invention which is characterized in that it comprises
a) a cylindrical central body comprising at least three evenly distributed expansion holders as well as one cylindrical part provided with threads, whereby the expansion holders are arranged to receive at least each a radially movable expansion means, and whereby the cylindrical part being provided with threads is arranged to receive one controlling device influencing the radially movable expansion means for obtaining a outwardly directed movement,
b) a first cylindrical shaft axially and rotatably mounted arranged in the central body and comprising a second controlling device arranged in the end thereof facing away from the central body,
c) an axially and rotatably arranged shaft in said second shaft, which shaft in its end receives at least three evenly distributed second expansion holders, which are arranged to receive at least each one radially movable second expansion means, whereby said second controlling device is arranged to influence said second expansion means for obtaining an outwardly radially directed movement; and
d) at least one device for checking the influence of the respective controlling device for radially outwardly directed movement of the respective expansion means.
By means of the present invention it is achieved that a flange can be readily fixed to a tube for subsequent welding of the flange onto the tube, whereby the flange will be correctly positioned in relation to the tube both regarding distance, angle as flange hole relationship.
Further characteristics of the present invention will be apparent from the accompanying claims.